I am not sure if your issues are the same as mine where, but I bought a sainsmart 3.2" TFT LCD Screen about a month ago and had roughly the same issues, it ending up being that the touch screen was just installed upside down?
So to fix that I now have to subtract the y-axis value I want from 240 to get the correct response...
Kind of annoying, but it still works. I am really not thrilled with sainsmart to be honest, they have such a wide variety of products that all seem to work, I just don't understand why they can't provide information about how to use them with the products.